I just can't pin this down...

[Benny26 0]

Hi guys, have a headache over this one.Ok, so i've been all over the forum here trying to find an answer to tweaking the AI cruise speed of any given plane (using the CFG and AIR files)...I've found some tips but nothing seems to work for me.I'm not a "noob" when it comes to the .cfg and .air files, by any means, i've been tweaking around for awile now. It's just now i've gotten around to modding the cruise speed, i've hit a wall (the answer's probably staring me in the face somewhere).I'm trying to set the correct cruise speed for an A320-200 at 0.78 mach (270 KIAS, 35000 ft), but it's sticking and hovering at 238 KIAS at 35000 ft...Here's what i'm doing :I've set and saved a flight from EGBB (Birmingham) to LXGB (Gibraltar) with a 35000 ft altitude...Then i grab i cessna (or any plane) and park at LEXJ (Santander, north Spain). This airport is right under the direct GPS path.Then i open Traffic Explorer and set an A320-200 on the EGBB to LXGB flight about half way through (right over me at LEXJ,) then i view the aircraft...This is where i'm getting my cruise reading from, it should be a good way to take a reading, right?When the Aircraft first appears, it's doing the correct 270 KIAS. Then after i unpause and let it fly, it slows down to the 238 KIAS and stays there....Another thing is the cruise speed of the default 747; it should be 0.85 mach, but when i place that on my flight it slows to 0.77 mach and doesn't move (???):( Anyway, i've tried changing the reference speeds, tuning the drag, changing certain unknowns in the air file (that's stuff i don't know not actual 'Unknowns')....I've changed air intake, engine thrust, overspeed warnings...all to no avail.Can someone point me in the right direction?...I would be really thankfull after the week i've been toiling with this.Thanks

[tf51d 284]

Hi guys, have a headache over this one.Ok, so i've been all over the forum here trying to find an answer to tweaking the AI cruise speed of any given plane (using the CFG and AIR files)...I've found some tips but nothing seems to work for me.I'm not a "noob" when it comes to the .cfg and .air files, by any means, i've been tweaking around for awile now. It's just now i've gotten around to modding the cruise speed, i've hit a wall (the answer's probably staring me in the face somewhere).I'm trying to set the correct cruise speed for an A320-200 at 0.78 mach (270 KIAS, 35000 ft), but it's sticking and hovering at 238 KIAS at 35000 ft...Here's what i'm doing :I've set and saved a flight from EGBB (Birmingham) to LXGB (Gibraltar) with a 35000 ft altitude...Then i grab i cessna (or any plane) and park at LEXJ (Santander, north Spain). This airport is right under the direct GPS path.Then i open Traffic Explorer and set an A320-200 on the EGBB to LXGB flight about half way through (right over me at LEXJ,) then i view the aircraft...This is where i'm getting my cruise reading from, it should be a good way to take a reading, right?When the Aircraft first appears, it's doing the correct 270 KIAS. Then after i unpause and let it fly, it slows down to the 238 KIAS and stays there....Another thing is the cruise speed of the default 747; it should be 0.85 mach, but when i place that on my flight it slows to 0.77 mach and doesn't move (???):( Anyway, i've tried changing the reference speeds, tuning the drag, changing certain unknowns in the air file (that's stuff i don't know not actual 'Unknowns')....I've changed air intake, engine thrust, overspeed warnings...all to no avail.Can someone point me in the right direction?...I would be really thankfull after the week i've been toiling with this.Thanks

I believe AI cruising speed is set within the traffic file itself. In the uncompiled file, it's the aircraft.txt file Here's a sample.AC#100,490,"WoA_FSP_A306_GE_FDX-FedEx"490 is the cruise speed (TAS) set for this FedEx A306.

[Benny26 0]

I believe AI cruising speed is set within the traffic file itself. In the uncompiled file, it's the aircraft.txt file Here's a sample.AC#100,490,"WoA_FSP_A306_GE_FDX-FedEx"490 is the cruise speed (TAS) set for this FedEx A306.

Hey, thanks for your reply.I know what you're saying here..but i think i've been down that road already.The "AC#100,490 ect..." is from an aircraft file for Traffic Tools, correct?....I don't use TT, i much prefer Traffic Database Builder but the stuff is almost all the same.Anyway, i've already compiled a test flight (set the correct cruise speed) and followed it out and up to cruise level using another AC in slew...It still hangs back in its speed.:( I read from a guy in another topic that for setting the cruise speed he toggles around with the drag flight tuning. I've been trying that and it hasn't been working for some reason.

[Reggie_Fields 0]

AI aircraft flight dynamics are built for and focused on landing behavior, to make a decent approach and clear the runway quickly. That is one reason most AI aircraft including B747 and other heavies fly at a weight under 110,000 lbs. Cruise speed is really not a concern to most people in AI because the planes only fly a maximum of about 100 nm if they are crossing your active AI zone. Normally when folks check AI, they are in descent.The reason you can't get the cruise speed higher is because the engine power, the drag factors, the aircraft lift - all are not sufficient to maintain that speed. The AI engine will generate the aircraft in the air at the altitude and speed from the traffic file. After that point aircraft behavior is controlled by the flight dynamics.You can spend a lot of time and effort learning how to tweak flight dynamics - but you also need to check the impact of your changes on takeoff and landing behavior of the aircraft. Such learning is always useful to better understand how FS works. Or you might want to try Jan Martin's alternate flight dynamics - http://janswebsites.110mb.com/flightsim/ -believe his FD come closer to the cruise speed you are wanting.

[Benny26 0]

AI aircraft flight dynamics are built for and focused on landing behavior, to make a decent approach and clear the runway quickly. That is one reason most AI aircraft including B747 and other heavies fly at a weight under 110,000 lbs. Cruise speed is really not a concern to most people in AI because the planes only fly a maximum of about 100 nm if they are crossing your active AI zone. Normally when folks check AI, they are in descent.

I'm just being padantic that's all. I've got some free time so i thought i'de tweak all my aircraft to closely fit their real specs as to enhance the FS AI experience, as it were. I'm doing all tests; Takeoff, landing and roll, cruise speed (and of course setting the correct fuel and weight specs). The landing roll is the most simple of all (the reverse thrust), if only others were the same.Boeing 747, at 110,000 lbs? I'm not sure that's right...One guy (an FD tweaker) said in another thread that MORE weight increases the landing speed?...I'll have to check that out myself i think.

Reggie_Fields said:The reason you can't get the cruise speed higher is because the engine power, the drag factors, the aircraft lift - all are not sufficient to maintain that speed. The AI engine will generate the aircraft in the air at the altitude and speed from the traffic file. After that point aircraft behavior is controlled by the flight dynamics.

This speed on placement is happening to me. After i place the AC on the flight it's at 280 KIAS (correct cruise), then it slows by 50 knots....So you're saying increase the engine thrust, reduce the drag, tweak the lift and i should see some movement...Ok, i'll have a go at that three pronged attack and see what goes..Although i think i've tried the engine thrust trick already.

Reggie_Fields said:You can spend a lot of time and effort learning how to tweak flight dynamics - but you also need to check the impact of your changes on takeoff and landing behavior of the aircraft. Such learning is always useful to better understand how FS works. Or you might want to try Jan Martin's alternate flight dynamics - http://janswebsites.....com/flightsim/ -believe his FD come closer to the cruise speed you are wanting.

The only problem with learning flight dynamics is there's no big tutorials around to really give you a big leap. I've read Bob Chicilo's little offering and it was rather good, but not big enough for me. I've been to Jan Martins's site already and downloaded alot of stuff (Great site :( )...I might go have another look now you've mentioned it.